Non-silver photosensitive composition sensitized with rubrene

ABSTRACT

NON-SILVER PHOTOSENSITIVE COMPOSITIONS ADAPTED TO BE DEVELOPED BY OPTICAL MEANS, SAID COMPOSITIONS BEING PROVIDED WITH SENSITIVITY EXTENDING INTO THE RED BY THE ADDITION THERETO OF MEROCARBOCYANINES OR A MEROCYANINE.

United States Patent O US. Cl. 96-90 8 Claims ABSTRACT OF THE DISCLOSURE Non-silver photosensitive compositions adapted to be developed by optical means, said compositions being provided with sensitivity extending into the red by the addition thereto of merocarbocyanines or a merocyanine.

The invention herein described was made in the course of or under a contract or subcontract thereunder, with the Systems Engineering Group, Air Force Systems Command.

This invention relates to photosensitive non-silver compositions, such as those described in US. Pats. 3,042,515 and 3,095,303 and improvements thereon, described in copending US. patent applications, including Ser. No. 696,100 filed Jan. 8, 1968 and Ser. No. 711,832 filed Mar. 11, 1968. More particularly, it relates to a means for extending the spectral response of such compositions.

The photosensitive compositions described in the earlier of the above noted pending patent applications include compositions comprising the following or their equivalents 4-p-dimethylaminostyryl quinoline (other dye base, e.g.

as in US. Pat. 3,095,303)

triaryl compound of P, As, Sb or Bi triphenylamine (or similar base) 2,6-di-tert-butyl-p-cresol or other stabilizers iodoform (or other compounds having a single carbon atom attached to three halogen atoms) and polystyrene or other film-forming binder.

Suitable proportions are set forth in the examples in the above application and are incorporated herein by reference.

It has also been disclosed that the photographic response of the composition is enhanced by treating the styryl quinoline with an alkali metal hydroxide, as described in the second of said above noted applications. Briefly, this treatment consists of digesting the dye base with an appropriate alkali metal hydroxide and the isolation of the stabilized dye base by precipitation and vacuum drying.

The present invention is directed to the extension of the spectral sensitivity to the green portion of the spectrum of such compositions by the addition of a polynuclear hydrocarbon to the composition and further toward the red portions of the spectrum by the addition of an indanedione or a rhodanine compound.

The invention will be better understood by reference to the several figures which depict the relative sensitivity of two otherwise identical compositions, one of which repre sents the prior art and the other of which represents the improvement obtained by the present invention.

FIG. 1 depicts the spectral sensitivity of a composition as defined in Example 1 and also the spectral sensitivity of a second composition to which rubrene has been added to enhance the spectral sensitivity.

FIG. 2 depicts a similar comparison, except that the added constituent is 3-ethyl-5-[l-methyl-4(1H)-quinolylidene)-ethylidene]-rhodanine instead of rubrene.

3,578,456 Patented May 11, 1971 FIG. 3 is a similar comparison in which the added compound is 2 [(3 ethyl-2(3H)-benzoxazolyidene)-2-butenylidene]-1,3-indanedi0ne instead of rubrene.

EXAMPLE 1 One graph of the three figures was obtained by preparmg a photosensitive composition comprising:

50 mg. 4-p-dimethylaminostyryl quinoline 50 mg. triphenylamine 50 mg. 2,6-di-tert-butyl-p-cresol 200 mg. iodoform 4.0 cc. 10% polystyrene in benzene The composition was prepared by adding the several constitutents, preferably in the order given, to a 10% solution of polystyrene in benzene.

After thorough mixing to insure uniformity, the resulting composition was spread on a film of Mylar or glass or other suitable substratein a wet thickness of 0.0015 inch-by means of a doctor blade or any other conventional coating technique. Paper or other absorbent substrate may be utilized in which case the substrate itself serves as the binder and hence some or even all of polystyrene can be omitted from the composition when it is applied to such a substrate. After the solvent had evaporated and the resulting film had dried, it was photographically exposed for the purpose of determining its response to filtered light of selected wavelengths. The latent image is developed to a visible image by exposing the entire film to radiant energy of an appropriate wavelength (600- 800 m for a period of time in the range of 15 to 300 seconds, the wavelength being selected so that the radiant energy falling on the unexposed portions of film did not contain radiation which would fog the non-image areas of the film. After development the film is heated at C. in moving air for approximately 2 minutes in order to fix the image. The amount of energy required to obtain a density of the image obtained by optical development equal to 1 density unit, is a measure of the spectral sensitivity of the film and is shown in the graph labelled Example 1 in FIGS. 1, 2 and 3.

The same composition was prepared in the identical way, except that 2 mg. of rubrene were added to the composition before the addition of triphenylamine. (The exposure and development were the same as before.) The resulting increase in spectral sensitivity is shown in FIG. 1.

In FIGS. 2 and 3 the cross hatched area represents the increase in spectral sensitivity produced as a result of adding the compound named in the figures to the composition of Example 1.

In the above compositions, the several constituents may be replaced by their equivalents, e.g., as described in earlier filed applications. For example, instead of the iodoform used in Example 1, carbon tetrabromide and other halogen containing organic compounds can be used, as described in US. Pat. No. 3,042,514, and instead of the specific styryl quinoline, other related higher 'vinylidene homologues can be used, as described in US, patent application Ser. No. 696,100 filed Jan. 8, 1968.

As shown in FIG. 2, sensitivity to the visible may be extended even further into the red region by incorporation of one or more mercocarbocyanines into the composition of Example 1.

Merocarbocyanines which have been found to be particularly effective include those represented by the following generic formula:

BINUCLEAR MEROCYANINES --z 0 R-I I- oH- oH).. 1b=(oH-oH)m ,=o o=0 wherein R represents a member selected from the group consisting of alkyl and aralkyl groups (including carboxyalkyl and sulfoalkyl groups), n represents a positive integer of 1 to 2, m represents a positive integer of from 1 to 4, Q and Z represent the non-metallic atoms necessary to complete a heterocyclic nucleus containing from to 6 atoms in the ring.

A specific member of this general class of compound is 3-ethyl-5-[ (1-methyl-4( lH)-quinolylidene)-ethylidene] rhodanine.

The spectral sensitivity curve is given by FIG. 2

mg. of merocyanine added to Example 1).

Formula:

i C-N-CzHs H3O- =CHCH=C ll s Merocyanines of the following formula:

wherein R is selected from the group consisting of lower alkyl, aryl and aralkyl; Y represents the non-metallic atoms necessary to complete a heterocyclic nucleus with from 5 to 6 atoms in the heterocyclic ring; n is an integer of from 1 to 2; and Q represents the nonmetallic atoms necessary to complete a five-membered or six-membered heterocyclic nucleus.

A specific member of this general class of compound is 2 [(3 ethyl 2(3H) benzoxazolylidene) 2 butenylidene] 1,3-indanedione.

The spectral sensitivity curve is given by FIG. 3 (1-2 mg. of merocyanine added to Example 1).

Formula:

0 II o o r i 02H; 0

What is claimed is:

1. A non-silver photosensitive composition exhibiting the spectral response of the composition and also a spectral response in the green region of the spectrum, said composition consisting essentially of (1) at least one styryl quinoline dye base; (2) at least one triaryl compound of P, As, Sb or Bi; (3) at least one organic compound having a carbon atom to which at least three halogen atoms are attached, the atoms being Cl, Br or I atoms; and (4) rubrene.

2. The composition of claim 1 wherein the organic halogen compound is iodoform.

3. The composition of claim 1 wherein the composition contains, as an additional ingredient, a compound which extends the sensitivity further toward the red region and selected from the group consisting of merocyanines.

4. The composition of claim 3 wherein the additional ingredient is 2- (3-ethyl-2 3H) -benzoxazolylidene) -2-buttenylidene] -1, 3 -indanedione.

5. The composition of claim 1 wherein the triaryl compound is triphenylstibine.

6. The composition of claim 3 wherein the additional ingredient is 3-ethyl-5- 1-methyl-4 1H) -quinoly1idene)- ethylidene] -rhodanine.

7. The composition of claim 3 wherein the additional compound is a binuclear merocyanine represented by the generic formula Q R-I I-(oH=oH I-o= o11-oH)m-1o o=o wherein R represents a member selected from the group consisting of alkyl and aralkyl groups, including carboxyalkyl and sulfoalkyl groups, n represents a positive integer of l to 2, III represents a positive integer of from 1 to 4, and Q and Z represent the non-metallic atoms necessary to complete a heterocyclic nucleus containing from 5 to 6 atoms in the ring.

8. The composition of claim 3 wherein the additional compound is merocyanine represented by the generic References Cited UNITED STATES PATENTS 7/ 1963 lSprogue et a1. 96-90 4/1968 Fichter 96-90 NORMAN G. TORCHIN, Examiner R. E. FIGHTER, Assistant Examiner 

